Embodiments of this application disclose a method for obtaining a motion vector, including: determining a reference block of a to-be-processed block, wherein the reference block and the to-be-processed block have a preset spatial correlation, the reference block is obtained based on a prediction block of the reference block determined by a refined initial motion vector, the refined initial motion vector is obtained based on an initial motion vector and one or more preset motion vector offsets, and the initial motion vector is obtained based on a predicted motion vector of the reference block; and using the initial motion vector as a predicted motion vector of the to-be-processed block.